Mathematical modelling of the loss of tissue compression responsiveness and its role in solid tumour development

This paper presents a mathematical model of normal and abnormal tissue growth. The modelling focuses on the potential role that stress responsiveness may play in causing proliferative disorders which are at the basis of the development of avascular tumours. In particular, we study how an incorrect sensing of its compression state by a cell population can represent a clonal advantage and can generate hyperplasia and tumour growth with well-known characteristics such as compression of the tissue, structural changes in the extracellular matrix, change in the percentage of cell type (normal or abnormal), extracellular matrix and extracellular liquid. A spatially independent description of the phenomenon is given initially by a system of non-linear ordinary differential equations which is explicitly solved in some cases of biological interest showing a first phase in which some abnormal cells simply replace the normal ones, a second phase in which the hyper-proliferation of the abnormal cells causes a progressive compression within the tissue itself and a third phase in which the tissue reaches a compressed state, which presses on the surrounding environment. A travelling wave analysis is also performed which gives an estimate of the velocity of the growing mass.

Faecal elastase 1 in children with cystic fibrosis

Recently, a new ELISA kit for determination of elastase 1 in faeces has become commercially available. Studies in patients with chronic pancreatitis have indicated that it is a simple and sensitive test of exocrine pancreatic function. The aim of this study was to assess the clinical value of this new test in cystic fibrosis. A total of 72 children were studied: 27 who were healthy, 22 with cystic fibrosis and 23 with non-pancreatic disorders. Oral pancreatic extracts were not discontinued in the children with cystic fibrosis. A small sample of faeces was collected from each subject for elastase 1 concentration and chymotrypsin activity determination. In all of the healthy children and most of those with non-pancreatic disorders (20/23), elastase 1 concentrations were greater than 500 microg/g; in contrast, the vast majority (20/22) of children with cystic fibrosis had very low values (less than 20 microg/g). The differences between children with cystic fibrosis and the other two groups were highly significant (P < 0.001). With a cut-off level of 132 microg/g, the sensitivity and specificity of faecal elastase 1 for the determination of exocrine pancreatic insufficiency were 96% and 100%, respectively. The specificity of faecal chymotrypsin was 96%, but its sensitivity was not calculated since the children with cystic fibrosis continued to take pancreatic extracts during the study.

CONCLUSION

The determination of faecal elastase 1 concentration is a simple and reliable means of assessing exocrine pancreatic function in children with cystic fibrosis. Results are not influenced by non-pancreatic disorders or by enzyme supplementation.

[Gastric carcinoma. Our experience]

This study analysed 66 cases of gastric cancer from 1985 to 1992. Twenty-seven patients (41%) has been treated with anti-H2 drug, either medical care or Jerkily "a la demande": 12 patients have been treated several years. Of the 66 patients: 52 (89%) were operated on while the other 16 received medical treatment because of the extension disease and their precarious condition. Long-term 35 (67%) patients (of the 52 operated) died four years later, independently of the stage and PKT of the first and the second level. The 27 patients treated with anti-H2 drug showed the most undifferentiated grading and 88% belong to the third and the fourth stage; moreover 81% underwent first diagnostic endoscopy notwithstanding a clinical and surgical history of gastric ulcer. Is it possible, therefore, that anti-H2 drug delay the diagnosis.

Breast feeding and acute lower respiratory infection

The association between breast feeding and acute lower respiratory infection (ALRI) was studied in a case-control study in southern Italy. Two groups of children were studied: the first group comprised 73 infants, aged 0-6 months, whose diagnosis was pneumonia or bronchiolitis; the second group included 88 infants less than 12 months of age with a diagnosis of pertussis-like illness. Control infants were two groups of infants admitted to the same ward. Compared with controls, infants in the first group were less likely to have been breast fed (odds ratio 0.42, 95% CI 0.19-0.90). The protection conferred by breast feeding was stronger among infants who were receiving human milk at the time of admission (odds ratio 0.22, 95% CI 0.09-0.55) and was absent among those infants who had stopped breast feeding for two or more weeks before admission. Among infants who were severely ill, breast feeding was less likely than among those with milder illnesses. There was evidence in the stratified analysis of effect modification by the presence of other children in the family. Among the infants with pertussis-like illness, the incidence and duration of breast feeding were not different compared with controls. The results suggest that breast feeding has a strong protective effect against ALRI in industrialized countries also. No protection seems to be conferred by human milk against pertussis-like illness.

[Palliative endoscopic treatment of esophageal neoplastic stenosis]

The authors examined a series of 231 patients suffering from unoperable neoplastic dysphagia of the esophagus and treated using prevalently palliative endoscopic methods (photocoagulation and/or intubation) during the period 1980-1991. They draw the following conclusions: a) endoscopic methods are better than surgical techniques; b) there are a greater number of indications for endoscopic intubation than for photocoagulation (approximately 2 to 1); c) some situation which are indicated for photocoagulation are not contraindicated for intubation; d) the sole contraindication for intubation is stenosis in which the proximal limit is less than 2 cm from the upper esophageal sphincter; e) contraindications for photocoagulation are long stenoses and/or those of the infiltrating type, and/or involving the upper third of the esophagus; f) sometimes the two methods may be complementary in the sense that intubation may be preceded by a few photocoagulation sessions in order to necrotize the vegetating portion of an infiltrating tumour; g) it is best to choose intubation wherever possible since this technique is less expensive and the quality of remaining life better, even if the percentage of severe and generally fatal complications (perforation) is still too high; h) the possible introduction of expandable metal prostheses might increase indications for intubation and reduce the number of severe complication.

[Palliative endoscopic intubation of esophago-gastric neoplastic stenosis: analysis of factors that may influence immediate results]

The paper examines a series of 172 patients undergoing endoscopic intubation with plastic stent due to unoperable esophago-gastric tumoral stenoses during the period 1980-1991. An analysis of the data enabled the following conclusions to be drawn: (1) The majority of perforations occur during the treatment of distal stenoses (15%), anastomotic stenosis (20%) and extrinsic compression stenoses (23% vs 7% in the case of stenosing primary esophageal neoplasia). (2) Severe respiratory problems may occur during treatment of cervical stenoses. (3) Malfunctioning of prostheses is more frequent in the treatment of cardias stenosis (10%). Having a few technical comments on the subject of passing the guide thread through the most twisting and narrow stenoses, the authors express the wish that expandable metal prostheses will be more widely used in order to render the method less traumatic, increase the percentage of success (extending the indications regarding the site and type of stenosis) and reduce severe complications.

Breast-feeding and urinary tract infection

A case-control study was conducted to study the association between breast-feeding and urinary tract infection. Case patients were 128 infants aged birth to 6 months with urinary tract infection. Control infants were 128 infants admitted to the same ward with an acute illness. The results support the hypothesis that breast-feeding protects infants against urinary tract infection.

[CEA, GICA, TPA, fibrinopeptide-A, gamma-GT and gastric cancer. A contribution to the rationalization of a combined assay]

CEA, GICA, TPA, Fibrinopeptide-A (FpA) and Gamma-GT serum levels were evaluated in 312 patients affected by gastric cancer, to assess their effectiveness in diagnosis, evaluation of disease extension and follow-up of gastric cancer. In 204 patients neoplasia was limited to the stomach, in 108 liver metastases, ascertained by ultrasonography and/or TAC, were present. CEA was increased in 224 cases (71.8%); mean values were significantly higher in metastatic patients than in metastasis-free group (p less than 0.001), but overlap of values between the two groups was observed in about one third of cases. GICA was increased in 268 patients (86%) and TPA in 306 (98%), without significant differences between metastatic and metastasis-free group. FpA was increased in all patients; when metastases were present it was significantly higher than in metastasis-free patients (p less than 0.001), with negligible overlap of values between the two groups. Gamma-GT was normal in 202 metastasis-free patients (99%) and increased in 105 patients with liver metastases (97%). On the basis of these data CEA does not seem to have striking diagnostic sensibility nor reliability in differentiating presence from absence of liver metastases in patients with gastric cancer. Combined assay of TPA, FpA and Gamma-GT seems to be the most reliable serological approach in diagnosis, staging and follow-up of gastric cancer.

Serum and erythrocyte levels of magnesium in microcytosis: comparison between heterozygous beta-thalassemia and sideropenic anemia

In thalassemia erythrocyte cation permeability is increased, but the increment in ATPase-dependent cation pumps maintains normal concentrations of Ca++, Na+ and K+. In this study we investigated erythrocyte concentrations of Mg++ in heterozygous beta-thalassemia and in microcytic sideropenic anemia. Twenty-five healthy controls, 40 heterozygous beta-thalassemics and 25 patients with sideropenic anemia were studied. Erythrocyte Mg++ was assayed either by atomic absorption or by standard laboratory methods. Erythrocyte Mg++ was significantly lower in the beta-thalassemia group than in the other two groups (p less than 0.001). Serum magnesium was significantly lower in sideropenic anemia patients than in beta-thalassemics and in controls (p less than 0.01), whereas these latter two groups showed similar values. Our results suggest that the increment in ATPase-dependent cation pumps is not sufficient to maintain normal erythrocyte Mg++ concentrations in heterozygous beta-thalassemia. In sideropenic anemia cation permeability is not increased, therefore erythrocyte Mg++ is normal. Low serum Mg++ levels in sideropenic anemia could be explained by a primary Mg++ deficit associated with sideropenia.

Serum thymidine kinase in diagnosis and follow-up of the small cell carcinoma of the lung

Serum thymidine-kinase (sTK) was assayed in 48 males affected by small cell carcinoma of the lung (SCCL) at the time of diagnosis. On the same drawing carcinoembryonic antigen (CEA) and beta 2microglobulin (beta 2 microG) were assayed in 19 of these subjects. For staging, the criterion of limited (LD) and extensive (ED) disease was used. Mean sTK and CEA values were above normal range in both the LD and ED groups, while mean beta 2 microG value remained below normal range. Thirty-two patients were subsequently submitted to therapy; sTK was assayed at the end of each treatment cycle. Mean sTK concentrations differed depending on response to therapy. From the data obtained it is concluded that sTK assay is helpful for diagnosis of SCCL; CEA to a lesser extent, above all in association with sTK, and beta microG not at all. sTK assay can also be useful for prognosis and follow-up.

Coagulation disorders and tumor markers in the diagnosis of pancreatic cancer

Twenty patients (42-80 years old of whom 9 women) affected by instrumentally ascertained pancreatic cancer (7 cases were operated on) were studied. In all of them the following coagulation indices (fibrinopeptide A, FpA; beta-thromboglobulin, BTG; platelet factor IV, PF4; fibrinogen degradation products, XDP) and tumor markers (gastrointestinal cancer associated antigen, GICA; tissue polypeptide antigen, TPA; carcinoembryonic antigen, CEA; alpha-fetoprotein, or AFP) were assessed at the time of diagnosis, and 10 and 30 days after diagnosis, to test whether and which of the above parameters are more sensitive for entertaining the underlying affection. In both operated and nonoperated patients FpA was shown to be the most sensitive index. Lesser sensitivity was shown by XDP, GICA, and BTG. AFP proved to be quite useless as its serum levels constantly fell within the normal range.

Changes of magnesium concentrations in endurance athletes

Erythrocitary and serum magnesium (Mg) were determined in a group of 11 well-trained athletes before and after a 25-km running race, and in a group of 30 sedentary controls. The significant increase of mean erythrocitary Mg (EMg) concentration observed in the athletes after physical strain (2.58 +/- 0.34 mEq/l before, 3.10 +/- 0.45 mEq/l after the race: significance level = 5%) leads to the assumption that the possible Mg uptake is effected by the red blood cell to enhance some enzymatic reactions. The decrease of mean serum Mg concentration observed in the same subjects after the effort (1.70 +/- 0.14 mEq/l before, 1.64 +/- 0.15 mEq/l after the race) is not significant. The difference between mean Mg concentrations observed in the athletes' group before the race and in the sedentary group (EMg: 2.58 +/- 0.34 mEq/l in athletes, 3.67 +/- 0.38 mEq/l in sedentaries, significance level = 1%; serum Mg: 1.70 +/- 0.14 mEq/l in athletes, 1.96 +/- 0.15 mEq/l in sedentaries, significance level = 1%) suggests that athletes suffer from a Mg deficiency, partially due to physical exercise. The two hypotheses and the possible causes of the observed phenomena are discussed.

[Neoplasms of the duodenum. A description of 2 clinical cases]

Duodenal tumours are a rare pathology, hard to diagnose early because of the unsubstantial symptomatology even though, in recent years, with the advent of improved techniques, a larger number have found their way into the literature. Two cases of duodenal cancer, one an adenocarcinoma localised in the first portion of the duodenum and one a subpapillary leiomyosarcoma are reported. 2 and 5 years respectively after the operation, both patients are in good health and do not present signs of disease.

Efficacy of addition of exogenous lactase to milk in adult lactase deficiency

The efficacy of lactase by Kluyveromyces lactis in hydrolyzing milk lactose and reducing milk intolerance symptoms was tested in 52 proved lactose malabsorbers. The enzyme was added to milk administered to the patients, and H2 breath excretion (as an index of carbohydrate malabsorption), was determined by gas chromatograph technique, and milk intolerance symptoms were recorded. H2 mean excretion was 78.3 +/- 5.49 ppm after administration of intact whole milk 500 ml (test A), 43.5 +/- 4.99 ppm when lactase 2000 U was added to milk 500 ml immediately before administration (test B); 36.7 +/- 5.01 ppm when milk 500 ml was incubated for 12 h with lactase 1000 U (test C), and 29.7 +/- 4.35 ppm when the incubation was prolonged for 24 h (test D). Symptoms score was: test A = 5.85 +/- 0.56, test B = 3.71 +/- 0.45, test C = 2.77 +/- 0.63, test D = 1.7 +/- 0.68. A correlation index of r = 0.44 (p less than 0.01) was obtained between reduction in H2 mean excretion and reduction in symptoms score of a single individual. The addition of this lactase to milk seems to be effective in correcting lactose malabsorption, thus representing a convenient approach in milk intolerance.

[Ring chromosome 4 in twins]

A case of ring chromosome 4 in an eleven months old male child with severe mental retardation, microcephaly and craniofacial anomalies is described. The karyotype was: 46,XY, r(4) p16----q35). The patient shows only few elements of the Wolf syndrome, whose phenotype is observed in most of the other cases with analogue karyotype.

A cytochemical study of some enzyme activities in biliverdin-treated cell cultures

The authors studied the modifications of the activities of some enzymes in cell cultures submitted to the action of biliverdin. This biliary pigment rapidly induces a remarkable increase in alkaline phosphatase and ATP-ase activities and subsequently, an activation of acid phosphatase and beta-glucuronidase. On the contrary, 5'-nucleotidase and glucose-6-phosphatase activities remain unchanged. These results are discussed and compared with those obtained in our and other laboratories by using unconjugated bilirubin on different biological substrates.